Studies on biotechnical ovulation synchronization in young sows. 3. Report: ovulation onset, ovarian findings and results of fertilization after metallibur, 750 IU PMS, with and without 500 IU HCG with varied treatment time

Fourty-eight gilts were treated with Turisynchron-Pr?mix (Turi.) and PMS (750 IU; 24-hours a. Turi.). One-half of the animals receaved additionally 500 IU HCG (fourth day a. Turi.). Performing treatments (Turi., PMS, HCG) either between 8 and 9 a.m. or 3 and 4 p.m. resulted in 2 experimental (HCG) and 2 control (without HCG) groups, each consisting of 12 animals. Double insemination took place according to treatment times at the fifth or the fifth and sixth day a. Turi. The experimental animals underwent laparotomy at the sixth day between 9 and 12 a.m., the conerols between 1 and 4 p.m. at the sixth or 9 and 12 a.m., at the seventh day a. Turi. Oviducts were flushed either at laparatomy or on slaughter to establish fertilization. From 24 experimental animals 20 ones had ovulated between 42-53 h p. HCG, and at slaughter 22 did so. The period of ovulation is mainly assumed near and immediately after 42 h p. HCG. In controls ovulation could be established in 3 of 15 animals laparotomized up to 152 h a. Turi. and in 8 of 9 animals laparotomized up to 168 h a. Turi. At slaughter there were in all 22 animals of the 2 control groups which had ovulated. In the rate of ovarian cysts (25-33%) and fertilized ova no remarkable differences were found between the groups.     

Mathematical models of strontium-90 behavior in a "water--fresh-water fish spawn" system in several individual cases of radionuclide entry into bodies of water

A group of 72 gilts, aged between eight and nine months, were treated 20 days each by administration of 5 g Suisynchronpr?mix (Zinc Metallibur/Sui), followed by 24-hour treatment with 750 IU PMS (Prolosanserum). Fifty per cent of the group received 500 IU per animal of HCG (Gonabion) at 11 a.m., on the fourth day after Sui. All animals were artificially inseminated at 3.30 p.m. on the fifth day after Sui. and at 7.30 a.m. on the sixth day after Sui. Laparotomy was performed on 50 per cent of the HCG-treated and untreated animals in the afternoon of the sixth day after Sui. Animals with no recordable ovulation had to undergo another laparotomy in the morning of the seventh day. The above approach resulted in regrouping by four therapeutic categories: 1. HCG with laparotomy, 2. No HCG, 3. HCG with no laparotomy, 4. No HCG and no laparotomy. In the afternoon of the sixth day after Sui (51-56 hours after HCG) ovulation had begun in all 17 measurable animals of the first group, but only in one of 18 animals of the second. The animals were slaughtered between the seventh and twelfth days after Sui, and the following ovulation percentages were established: 100 per cent in the first group, 83.3 per cent in the second, 55.6 per cent in the third, and 72.2 per cent in the fourth. The animals that had been given HCG treatment (Groups 1 and 3) were found to be superior in terms of percentual ovulation to the untreated animals (Groups 2 and 4). However, Group 2 was the only group that had been exposed to the extraordinary stress of two laparotomies, and this should be borne in mind for evaluation. Ovarian cysts (more than 10 mm) began to develop on the eighth day on the laparotomised groups (1 and 2) and on the tenth day on the non-laparotomized groups (3 and 4). Cysts developed in 41.1 per cent of all animals in Group 1, 38.9 per cent in Group 2, 27.8 per cent in Group 3, and 22.2 per cent in Group 4. Therefore, cyst formation is thought to have been stimulated by laparotomy. Ovocyte tests suggested fertilisation of all animals in the first group. The embryonation rates of the second, third, and fourth groups are discussed with reference to the dates of insemination.     

The course of ovulation after biotechnical puberty induction in young sows

Four experimental series were applied to 342 prepuberal young sows to establish ovulation developments. Different periods of time were allowed to elapse between injection and slaughter. Injected were 400 IU PMS/200 IU HCG or 500 IU PMS/250 IU HCG. Onsets of ovulation were found to be highly differentiated and variable. Some of the animals had completed ovulation 72 hours after application of gonadotrophin, whereas in others had not even started 168 hours after such application. In the majority of all sows involved in the experiments ovulation occurred 96--144 hours from application of the gonadotrophis hormone. In other words, fertile semen should be present in the genital tract of sows in that period of time, if the concept of deadlineoriented insemination is followed.     

Daily measurements and in-vitro effects of human chorionic gonadotrophin in the early luteal phase

The purpose of the present study was to analyse daily measurements of human chorionic gonadotrophin (HCG) in in-vitro fertilization (IVF) cycles and to reproduce the effects of HCG in vitro using human granulosa-luteinized cells from the same patients. The study population consisted of nine women undergoing IVF because of tubal infertility in whom blood was drawn every 24 h from the day of the ovulatory dose of HCG (10,000 IU) until 6 days after ovum pick-up. Granulosa-luteal cells from the follicular aspirates were collected and cultured in vitro up to 6 days in the presence of increasing concentrations (0, 0.01, 0.1, 1.0 and 100.0 IU/ml) of HCG. Serum progesterone and HCG in vivo as well as progesterone accumulation in vitro on days 2, 4 and 6, were the main outcome measures. Maximum HCG concentrations (0.25 IU/ml) were reached the day before ovum pick-up, and continuously decreased until day 6 after ovum retrieval. HCG did not stimulate progesterone production in vitro at any dose tested until day 6 after ovum pick-up. Then, 0.01 IU/ml resulted significantly (P < 0.05) stimulatory compared to controls, while 1.0 IU/ml was inhibitory (P < 0.05). It is concluded that HCG supplementation in an IVF cycle is unnecessary until day 6 after ovum pick-up. On day 6, progesterone production is stimulated with very low concentrations of HCG.     

Studies on various dosages of PMS and HCG in biotechnical puberty induction in young sows

The PMS and HCG doses by which to induce puberty and successfully use the first induced oestrus were tested in three experimental slaughter series on 197 prepuberal young sows. An injection of 500 International Units of PMS and 250 IU of HCG was found to bear greatest promise. While higher dosages gave higher rates of ovulation and, following insemination, higher numbers of embryos, pregnancy rates as a whole dropped severely. Since a very high percentage of all animals involved exhibited follicle stimulation, following such treatment, while only half of them displayed tolerance, it is strongly suggested to use for all animals deadline-oriented rather than toleranceoriented insemination.     

Prolactin delays gonadotrophin-induced ovulation and down-regulates expression of plasminogen-activator system in ovary

This study was conducted to determine whether prolactin (PRL) suppresses gonadotrophin-induced ovulation and disturbs the co-ordinated gene expression of tissue type plasminogen activator (tPA) and plasminogen activator inhibitor type-1 (PAI-1) in rat ovary. Immature female rats were injected with 10 IU pregnant mare's serum gonadotrophin to stimulate follicle growth, and 48 h received different doses of prolactin followed by 7 IU human chorionic gonadotrophin (HCG). The oviducts were examined for the presence of ova, and the amounts of tPA and PAI-1 mRNA present in the ovary were measured at various times after the hormone treatment. PRL had no significant effect on ovarian weight but caused a dose-dependent decrease in ovulation number. In the control animals receiving HCG alone, 13.3 +/- 1.3 (mean +/- SEM) ova/oviduct were found; while in animals receiving HCG plus 50, 100 or 200 microg PRL, the ovulation number was dose-dependently suppressed by 53.6, 66.9 and 76% respectively at 18 h after treatment. PRL suppression of HCG-induced ovulation was time-dependent. By 24 h after treatment, the number of ova in the oviducts in HCG- and HCG plus PRL-treated groups was not significantly different. PRL also suppressed HCG-induced tPA gene expression in a dose- and time-dependent manner. At all time points examined, tPA mRNA content of whole ovaries and granulosa cells (GC) in PRL-treated groups was lower than in the HCG-treated controls. The activities of PAI-1 in ovarian extracellular fluid (OEF) and PAI-1 mRNA in the theca-interstitial cells (TI) in the PRL-treated groups were higher than in the HCG-treated controls. The highest stimulation by PRL of PAI-1 activity in OEF and of PAI-1 mRNA in TI was observed at 9 h and 6 h after HCG treatment respectively. The localization of tPA and PAI-1 antigens in the ovaries was consistent with changes in the mRNA and activity levels. These data suggest that PRL temporarily delays, but does not completely inhibit, HCG-induced ovulation, which may be caused by a suppression of PA-mediated proteolysis.     

Spontaneous conception and intrauterine pregnancy in a symptomatic missed abortion of ectopic pregnancy conceived in the previous cycle

We encountered a rare case of combined intrauterine and extrauterine pregnancy that occurred following separate spontaneous ovulations. A 33 year old woman visited our hospital with the chief complaint of abdominal pain on April 16, 1993. Her last menstruation was from March 23 for 6 days. However, the urinary human chorionic gonadotrophin (HCG) on April 19 was 1024 IU/l. Pelvic examination and ultrasonography indicated an extrauterine pregnancy, which was confirmed by laparotomy and histological identification of trophoblast cells. The urinary HCG concentration markedly decreased after the operation. However, the HCG level increased again on the fifth post-operative day, and a gestational sac (11 mm) was identified in the uterine cavity on the 11th post-operative day, indicating that this intrauterine pregnancy was established following spontaneous ovulation which occurred before the removal of the extrauterine pregnancy. This case indicates that a combined pregnancy can occur not only after simultaneous multiple ovulations but also after the separate spontaneous ovulations.     

Artificial intranasal bacterial invasion in the newborn calf. 2. Artificial bacterial invasion using gram-positive and gram-negative strains

A micrococcal and a diplocaccal strain isolated from the nasal space of a clinically intact nursed calf were used for artificial bacterial invasion in the first phase of the experiment. Application of bacterial suspension prepared from those strains had no effect upon the rise of coli counts in the nasal secretion of nursed calves during their first days of age nor upon the morbidity or mortality of all 677 test animals in comparison to 665 controls. Therefore, an avirulent E.-coli strain was used in subsequent bacterial invasion experiments. The strain was retrievable up to the seventh day of age, the count having been about 10(5) bacteria per gram nasal secretion. Application of a bacterial suspension prepared from that E.-coli strain did not reduce morbidity and mortality among 820 test animals that were compared to 809 controls. Results are discussed in this paper with reference to literature.     

Initiation of periovulatory events in gonadotrophin-stimulated macaques with varying doses of recombinant human chorionic gonadotrophin

During in-vitro fertilization (IVF) cycles, a large bolus of human chorionic gonadotrophin (HCG) is used to induce periovulatory events, but the efficacy of lower doses is undefined. Following follicular stimulation in rhesus monkeys, oocyte nuclear maturation, IVF, granulosa cell luteinization and corpus luteum function were compared after injection of 100, 300 or 1000 IU recombinant HCG or 1000 IU urinary HCG. Bioactive HCG rose to peak concentrations within 2 h that were proportional to the dose administered (100 < 300 < 1000 IU, recombinant HCG = urinary HCG). The duration of surge values (>100 ng/ml) was also dose-dependent (0 h, 100 IU; 24 h, 300 IU; >48 h, 1000 IU, recombinant and urinary HCG). While the proportions of oocytes resuming meiosis and undergoing IVF were similar among groups, fewer animals yielded fertilizable oocytes following 100 and 300 IU (five of nine) compared to 1000 IU recombinant and urinary HCG (nine of 10). Peak values of serum progesterone in the luteal phase were similar, but declined 2 days earlier after 100 and 300 IU relative to 1000 IU recombinant and urinary HCG. Thus, 3-10 fold lower doses of HCG elicit low amplitude surges of short duration that induce periovulatory events such as re-initiation of oocyte meiosis and granulosa cell luteinization. However, oocyte fertilization and luteal function may optimally require surges of higher amplitude and longer duration similar to those produced by standard doses of 1000 IU recombinant or urinary HCG.     

A single dose of mifepristone induces ovulation in pseudopregnant rats

We used mifepristone (M) to evaluate the role of progesterone in maintaining pseudopregnancy. Cycling rats were made pseudopregnant (psp) by cervico-vaginal stimulation (CVS) on the day of estrus (day 0) and received 10 mg/kg M or vehicle (control groups) on day 3. Blood samples were taken at 06.00 h on days 4, 6 or 7 or at 18.00 h on days 3, 4, 6 or 10. M induced proestrus 2 days later (day 5), estrus on day 6, and a second prolonged diestrus afterwards. Prolactin and progesterone levels were similar in the control and M treated groups excepting on day 6, when both were reduced in the M-treated animals, and these rats were in estrus, suggesting a temporary impairment of luteal function. To demonstrate activated corpora lutea the endometrium was scratched on the fourth day of the first or second diestrus in additional control and M-treated groups. The deciduomal response was seen in the control and M groups after scratching the endometrium on day 4 of the first or second diestrus, respectively, but M blocked the deciduomal response in the first diestrus. Ovulation was confirmed by finding that 66.7% of the M-treated rats showed ova in the Fallopian tubes on the M-induced estrus and 4 out of 10 of the M rats placed with males on the M-induced proestrus showed spermatozoa in the vaginal smears. Half of these became pregnant, delivering 2 pups each. The results show that M can induce ovulation in psp rats, demonstrating that the anovulation observed after CVS is dependent on progesterone, yet luteal function persists after M in pseudopregnancy. Progesterone may act either by suppressing LH secretion or by permitting prolactin secretion, or both. Moreover, progesterone is required to maintain endometrial responsiveness.     

Hormonal profile during the follicular phase in cycles stimulated with a combination of human menopausal gonadotrophin and gonadotrophin-releasing hormone antagonist (Cetrorelix)

A third generation gonadotrophin-releasing hormone antagonist (Cetrorelix) was used during ovarian stimulation in 32 patients undergoing assisted reproduction, in order to prevent the premature luteinizing hormone (LH) surge. In all patients, ovarian stimulation was carried out with two or three ampoules of human menopausal gonadotrophin (HMG), starting on day 2 of the menstrual cycle. In addition, 0.5 mg of Cetrorelix was administered daily from day 6 of HMG treatment until the day of ovulation induction by human chorionic gonadotrophin (HCG). A significant drop in plasma LH concentration was observed within a few hours of the first administration of Cetrorelix (P < 0.005). Moreover, no LH surge was detected at any point in the treatment period in any of the 32 patients. A mean oestradiol concentration of 2111 +/- 935 ng/l was observed on the day of the HCG administration, indicating normal folliculogenesis. Like LH, progesterone concentration also dropped within a few hours of the first administration of Cetrorelix (P < 0.005). A 0.5 mg daily dose of Cetrorelix prevented a premature LH surge in all the 32 patients treated.     

LD 50 and selenium concentration in the organs of rabbits following oral administration of sodium selenite and testing of the toxicity of Ursoselevit-Pr?mix

LD50/24hr was established in the first of a series of experiments on 72 rabbits for orally applied sodium selenite. The dosage was 8.62 mg/kg live weight, the confidence interval being (1 - alpha = 0.95) +/- 0.13 mg/kg. The value was four times as high following intravenous application. Complete lethality was recorded from 15 mg Na2SeO3/kg live weight within 21 hours. Thirty-six animals were involved in the second experiment of the series. They had 50 or 100 per cent Ursoselevit-Pr?mix (30 ppm Se) in their rations. Body mass development of the test animals was superior to that recorded from the controls in the first 50 days, after which limit the former declined strongly in a few days. Their general condition worsened. Postmortem findings, following slaughter, included catarrhal enteritis, toxic liver dystrophy, scattered pulpous tumours in the spleen, and interstitial nephritis. In the third experiment (50 per cent Ursoselevit-Pr?mix with 60 ppm Se in the rations), the test animals developed better than the controls during the first two months, after which point they exhibited the same clinical symptoms as those observed in the second experiment, stopped to put on weight, and eventually turned cachectic. The pathomorphological findings were identical with those obtained from the second experiment. The selenium concentrations in the organs of the test animals all were much higher than those of the controls. Their amounts in excess to base values were up to eleven times in the blood, nine times in the liver, twelve times in the kidneys, and 13 times in the muscles.     

Development of Anaplasma marginale in salivary glands of male Dermacentor andersoni

The objective of this study was to clarify the role of oestradiol in luteal function by examining its effect on the oxytocin stimulation of 15-keto-13,14-dihydro-prostaglandin F2 alpha (PGFM) concentrations in cyclic mares. In the first experiment, three groups of mares (4 per group) were given a bolus injection of 17 alpha-oestradiol (1 mg), oestradiol (1 mg) or vehicle on days 7, 9, 11, 13 and 15 of the cycle. Six hours later the mares were challenged with 10 iu oxytocin intravenously and frequent blood samples were taken from 15 min before to 15 min after for measurement of PGFM. Results showed a significant stimulatory effect of oestradiol (five times greater than controls at day 11; P < 0.05), but not of 17 alpha-oestradiol, on the oxytocin stimulation of PGFM. As a relatively large dose was given systemically in this experiment, a second experiment was performed to introduce a dose that was more physiological into the uterus. Small Silastic spheres (1 cm diameter) were impregnated with or without oestradiol at a concentration that gave a release rate similar to that of embryos at day 12 (10 ng h-1). These were inserted (one per mare) into the uterus of two groups of mares (five per group) on day 7. The mares were challenged with oxytocin on days 9, 11, 13 and 15 of the cycle and blood samples were taken as before for determination of PGFM. The results showed that oestradiol enhanced (four times greater than controls at day 13; P < 0.05) the oxytocin stimulation of PGFM concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of platelet activating factor on embryonic development and implantation in the mouse

Platelet activating factor (PAF) was administered to female mice in order to investigate its effect on ovulation rate and on oocyte quality including their in-vitro embryonic development, implantation and uterine receptivity. In experiment 1, 4-week-old female mice were assigned to receive PAF or phosphate buffered saline for 4 consecutive days. On the second day of this treatment, pregnant mares' serum gonadotrophin was administered and human chorionic gonadotrophin (HCG) 48 h later, after which copulation occurred. Oocytes were collected on the following day and evaluated. The mean number of oocytes and zygotes (two pronuclear stage embryos) recovered from the PAF-treated group was not different from the control group (31 versus 27), but the proportion of zygotes was higher in PAF-treated group than in controls (83 versus 68%, P < 0.05, PAF versus controls). Although the rate of in-vitro first cleavage was not different in the two groups (82 versus 69% respectively), hatching was higher in the PAF-treated group than control mice (99 versus 83%, P < 0.01). In experiment 2, the in-vitro developed blastocysts from experiment 1 were transferred into the uterus of day 3 pseudopregnant PAF-treated or control recipients. Three different combinations of intrauterine transfer were performed; PAF embryo to control recipient (PAF-->C: n = 19), control embryo to PAF recipient (C-->PAF: n = 19), and control embryo to control recipient (C-->C: n = 22). Implantation and abortion were assessed on day 19 posttransfer. The implantation rate of C-->PAF (23.7%) was lower than C-->C (31.1%, P < 0.05), but was not different from PAF-->C (31.2%). Further, C-->PAF showed a higher abortion rate per embryo (29.6%) than PAF-->C (12.7%, P < 0.05), but was not different from C-->C (24.4%). In the present study, PAF administration enables females to produce oocytes with a higher potential for fertilization, in-vitro development and implantation, but has a detrimental effect on uterine receptivity to embryos.     

Beta-thromboglobulin plasma levels in the first week after myocardial infarction: influence of thrombolytic therapy

In vitro and in vivo studies have shown both an inhibition and an activation of platelets after thrombolysis in acute myocardial infarction. Plasma beta-thromboglobulin, a marker of platelet activity, was evaluated daily during the first week after myocardial infarction in 24 patients who received intravenous streptokinase (group 1) and 26 who did not (group 2). On admission, levels of beta-thromboglobulin, as compared to those in healthy subjects (35 +/- 9 IU/ml), were similarly augmented in group 1 (105 +/- 27 IU/ml) and in group 2 (115 +/- 30 IU/ml); 3 hours later, values averaged 191 +/- 58 IU/ml in group 1 (p < 0.001 vs baseline) and 95 +/- 28 IU/ml in group 2 (not significant vs baseline; p < 0.001 between the two groups). From the second to the seventh day, beta-thromboglobulin augmented in those patients in both groups with postinfarction angina. From day 5 to day 7, patients of group 1 without angina had lower beta-thromboglobulin levels than patients of group 2 who had no symptoms. The lowest levels of platelet activity were observed in group 1 reperfused patients. These data indicate that in myocardial infarction an early platelet activation takes place that is enhanced by thrombolytic treatment; recurrence of angina is associated with persistent activation; in the absence of recurrent angina, thrombolysis can limit late platelet activation.     

Surfactant replacement in adults and children with ARDS--an effective therapy?

[3H]-Thymidine radioautography showed that 0.005% p-aminobensoic acid (PABA) solution applied three times per day on penetrating wounds in central part of the adult rat cornea selectively stimulates proliferative activity of corneal stroma keratoblasts. In control rats, a curve showing changes in index of labeled nuclei in corneal stroma had two peaks, on the second and sixth day after injury (about 5 and 3%, respectively), whereas in animals receiving PABA treatment it had a single peak on the second day (about 12%). On days 7-14, indices of labeled nuclei in corneal stroma of both experimental and control rats become similarly low. No difference between experimental and control animals was revealed in indices of labeled nuclei in corneal epithelium: in both groups, corresponding curves had two peaks (about 9%) on the first and fifths days, and proliferation still continued two weeks after injury.     

Effect of dietary monensin on ovarian response following gonadotropin treatment in prepuberal heifers

Twenty prepuberal Charolais X Brahman-Hereford heifers were randomly assigned to be fed a concentrate containing either 0 mg (C) or 200 mg (M) monensin sodium/head/day. Coastal bermudagrass hay was fed ad libitum. Average daily gain was similar for the two groups. Each heifer received 1 mg of porcine follicle stimulating hormone (FSH-P) (Armour) at 0800 and 2000 hr on days 22 through 26 (10 mg total) and 2,500 IU human chorionic gonadotropin (HCG) on day 27. Flank laparotomy was performed on day 30, for examination of ovaries, and ovariectomy was performed on day 37. The average ovarian size +/- standard error at day 15 ws 3,730 +/- 66 mm3 and 1,848 +/- 55 mm3 for groups M and C, respectively (P < .025), as measured by rectal palpation. Numbers of ovulation sites measured on day 30 were 9.1 +/- 2.2 and 4.9 +/- 1.8 per heifer for groups M and C, respectively (P < .01). After ovariectomy on day 37, heifers fed M were found to have greater ovarian weight (P < .05), more corpora lutea (CL) (P < .05), greater total luteal weight (P < .05), more follicles (P < .01) and greater weight of follicular fluid (P < .05) and stroma (P < .025) than controls. CL were analyzed for progesterone content by spectrophotometric procedures. Heifers fed M had slightly larger CL (P < .10) with progesterone concentrations similar to those in CL from controls. This resulted in more luteal progesterone per CL and more luteal progesterone per heifer in the M heifers than in the controls. Prepuberal heifers fed M, which caused the expected shifts in rumen fermentation and volatile fatty acid production, exhibited an enhanced ovarian response to gonadotropins compared to that exhibited by controls.     

Induction of ovulation in rabbits by pure urinary luteinizing hormone

In 18-week-old nulliparous rabbit does, ovulation was induced with 50 IU of pure urinary luteinizing hormone (LH; LH group), or 50 IU of human chorionic gonadotrophin (HCG; HCG group), in order to determine the effect of these treatments on 17 beta-oestradiol and progesterone concentrations, and on oocyte and embryo quality. Luteinizing follicles, recovered oocytes, progesterone concentration and grade 5 embryos were significantly reduced when pure urinary LH was used. Statistically significant correlations were found: (i) between oestradiol concentration and number of degenerated oocytes in both groups (positive); (ii) between oestradiol concentration and grade 1 and 2 embryos (negative), and grade 5 embryos (positive) in the HCG group; (iii) between progesterone concentration and metaphase II oocytes (negative), and between progesterone and grade 5 embryos (positive), in the HCG group; and (iv) between progesterone and oestradiol concentrations (negative) in the LH group. It seems that the oestradiol to progesterone ratio improves during the early luteal phase when ovulation is induced with LH, and that oestradiol and progesterone concentrations could play a role in determining oocyte and embryo quality.     

The subgenus persicargas (Ixodoidea: Argasidae: Argas). 25. Effect of temperature on diapause termination in female A. (P.) arboreus Kaiser, Hoogstraal and Kohls

Pubertal female rats received sodium pentobarbitone (PB; 45 mg/kg body wt) at various hours on the day of first pro-oestrus. Maximal blockade of ovulation, in about 60% of the rats, occurred after PB treatment at 12.00, 13.00 and 14.00 h. The number of small antral follicles (100-499 X 10(5) mum3) was reduced 1 day after PB treatment in both blocked and ovulating rats. In the ovaries of non-ovulating rats signs of stimulation by LH such as dispersion of cumulus cells, oocyte maturation and early luteinization were sometimes present; in ovulating rats cystic corpora lutea with entrapped ova were found in addition to normal corpora lutea. Gonadotrophin measurements after PB treatment (14.00 h) in pubertal and adult rats showed (at 17.00 h) reduced levels of both LH and FSH, these levels being lower in the adults. Gonadotrophin levels of blocked and ovulating pubertal rats overlapped. In PB-treated, pubertal rats in which ovulation was postponed by 1 day, vaginal oestrus was prolonged by 1 day and the subsequent dioestrus by 2 days. The pubertal rat is thus less sensitive to PB treatment than the adult. PB treatment of the younger animal influences not only the ovulatory process but also follicular growth and, presumably, the length of the approaching cycle.     

Lysosomal enzyme beta-glucuronidase. Release from regenerating liver after partial hepatectomy

In 12 dogs, 70% hepatectomy was performed to investigate the changes in serum lysosomal enzyme beta-glucuronidase activities, and to compare them with other liver functions and with the restoration of liver mass. Three dogs died within 24 hours without recovering consciousness from anesthesia, and one died on the fourth postoperative day because of hepatic insufficiency. The other eight dogs were killed at various postoperative times up to eight weeks. Regeneration of the remaining liver occurred rapidly after operation. The peak elevation of serum glutamic oxaloacetic transaminase activity was found on the first postoperative day, with a steady return to normal within two or three weeks. To the contrary, the serum activity of beta-glucuronidase decreased during the first three days, but increased substantially between the seventh and 14th postoperative day, when regeneration was considered to be maximum. The results seem to indicate that serial determinations of lysosomal enzyme activities in the blood can be a beneficial biochemical index for detection of progressing liver regeneration following partial hepatectomy.